1. Field
The present application relates, generally, to data encryption and, more particularly, to conditioning of data to be substantially immune to frequency analysis.
2. Description of the Prior Art
In an age that depends on the private exchange of sensitive information, it is critical to have encryption methods that are fundamentally secure and relatively easy to implement. Such methods should also be reasonably immune from ever-increasing computational power; brute force and nuanced cryptanalysis have become relatively easy to apply. To combat these and other attacks, the key lengths have become longer, and encryption/decryption algorithms have become significantly more complicated.
Encryption methods date back to at least the time of the ancient Greeks, and now take a multitude of forms. The most robust modern approaches (e.g., Advanced Encryption Standard and Triple Data Encryption Standard) increase effectiveness by combining basic methods, often including cryptographic primitives such as hash functions and cryptographically secure pseudorandom number generators (CSPRNGs), into cryptographic systems. Indeed, given the often complicated combinations of techniques and operations comprising modern ciphers, it is sometimes difficult to categorize methods that combine fundamental algorithmic concepts, such as those underlying block ciphers, stream ciphers, substitution, transposition, and permutation ciphers.
It is generally accepted that there is an inverse relation between what is secure in a provable sense and what is secure from a practical standpoint. It is, therefore, a common goal in cryptography to find methods that can rigorously demonstrate security, while at the same time being practical to implement. It is also critical that such methods not rely on algorithmic secrecy, but rather remain open to inspection and evaluation.